1) when measuring rainfall (Chills this is all you), and it comes to .5", is that .5" over a square inch or square foot or what? is that the same area where the measure rate of rainfall, ie .2" per hour?

2) on a dyno that measures power at the wheels is there a set gear to be in or can you put in the gear ratio for what you're in to compensate? Maybe I've got it wrong and it doesn't matter but considering you pull harder in 1st than 6th I figure that would have some impact on the numbers.

3) what is the explanation for a wheelie? is it extreme weight transfer, the back wheel accelerating faster than the front and "driving through" the front? Is a power wheelie one example but a clutch up something else?

1) when measuring rainfall (Chills this is all you), and it comes to .5", is that .5" over a square inch or square foot or what? is that the same area where the measure rate of rainfall, ie .2" per hour?

2) on a dyno that measures power at the wheels is there a set gear to be in or can you put in the gear ratio for what you're in to compensate? Maybe I've got it wrong and it doesn't matter but considering you pull harder in 1st than 6th I figure that would have some impact on the numbers.

3) what is the explanation for a wheelie? is it extreme weight transfer, the back wheel accelerating faster than the front and "driving through" the front? Is a power wheelie one example but a clutch up something else?

1) 0.5" (depth) of rainfall over a square inch is the same depth as 0.5" over a square foot, but the volume is 1/144 as much, since there is less area to collect it. To get the rate, measure the depth of the rainfall and divide by elapsed time in hours. (3" fell in 2 hours = 1.5"/hr). Next time it rains, put 2 containers out there of different sizes, and they will fill to the same depth. Of course, they have to have flat bottoms and be cylindrical.

#3 is a good question. What exactly is the physics that make a wheelie? I can't scientifically explain it. Maybe the front sprocket actually climbs the chain which makes the whole thing pivot around the rear sprocket? dunno but it sounds good lol

2) on a dyno that measures power at the wheels is there a set gear to be in or can you put in the gear ratio for what you're in to compensate? Maybe I've got it wrong and it doesn't matter but considering you pull harder in 1st than 6th I figure that would have some impact on the numbers.

Automatic 4 speed cars get dyno'd in 3rd, 5 or 6 speed manual cars get pulled in 4th. Any lower and the tires will spin on the dyno, making it pointless.

1) 0.5" (depth) of rainfall over a square inch is the same depth as 0.5" over a square foot, but the volume is 1/144 as much, since there is less area to collect it. To get the rate, measure the depth of the rainfall and divide by elapsed time in hours. (3" fell in 2 hours = 1.5"/hr). Next time it rains, put 2 containers out there of different sizes, and they will fill to the same depth. Of course, they have to have flat bottoms and be cylindrical.

thank you very much, I should've realized diameter would be the same all the way down. I think I had something tapered in mind

#3 is a good question. What exactly is the physics that make a wheelie? I can't scientifically explain it. Maybe the front sprocket actually climbs the chain which makes the whole thing pivot around the rear sprocket? dunno but it sounds good lol

come on, I want to verify my 48 horsepower...did you see the thread with the circle wheelies on a 250? 500 is twice as much as 250 so I can do them twice as good, maybe 3 times better if I do it with no gear

It has something to do with power transfer. Because the front sprocket rotates counter-clockwise, it transfers the torque from the motor, to the rear sprocket via the chain, which in turn transfers to the rear wheel. If you draw a line perpendicular from the ground to the center of the wheel, that will be your pivot element. Assuming traction is kept, once the moment created around the rear axle over comes the summation of the forces holding everything in front of the pivot element down, then the front wheel will start to rise.

2) so when a car is rated at 215 hp that's an average of all the gears?

Not really. Rated horsepower is usually measured at the crank, so it's only a function of engine rpm. Say a naturally aspirated car is rated at 200 hp. It's probably making that 200 close to red line, say 6000 rpm. So at like 3000 rpm, the engine is only making like 100 or less hp. You have a transmission so that the crank hp can be put to good use over a wide range of speeds (starting from a stop to cruising on the highway).

Not really. Rated horsepower is usually measured at the crank, so it's only a function of engine rpm. Say a naturally aspirated car is rated at 200 hp. It's probably making that 200 close to red line, say 6000 rpm. So at like 3000 rpm, the engine is only making like 100 or less hp. You have a transmission so that the crank hp can be put to good use over a wide range of speeds (starting from a stop to cruising on the highway).

thanks, but that was more of a smart ass retort to BWA...I didn't mean for you guys to think I'm retarded, I just like to know things and these are things I was curious about

The way I see #3 is simply the force turning the rear wheel giving so much traction and power to it that the front jumps... I think it also has to do with the line between the front and rear wheel... for example, if the front wheel had a 5" instead of 15-16-17" diameter, it would be hard/impossible to "pop a wheelie" because the force would be going towards the ground, instead of above the center line between the rear and front wheel... weight of the bike of course is a variable here, but it comes from the "jerk" which introduces enough force to lift up the front end... I could explain this in much better terms if it was a few years back when I asked a physics professor to explain it to me, but I'm tired, hungry and watching will and grace haha... in short, it's in the "jerk" haha

The rotational force created by the engine is being transferred to the ground by the tire at that exact axis point which forces the front end to rise. The rest of the bike is considered drag and the rear wheel will attempt to pass the rest of the bike forcing it to wheelie. That is why jet bikes don't really wheelie because the acceleration point is at the back of the bike above the rear wheel axis. They just go straight REALLY fast.

1) when measuring rainfall (Chills this is all you), and it comes to .5", is that .5" over a square inch or square foot or what? is that the same area where the measure rate of rainfall, ie .2" per hour?

2) on a dyno that measures power at the wheels is there a set gear to be in or can you put in the gear ratio for what you're in to compensate? Maybe I've got it wrong and it doesn't matter but considering you pull harder in 1st than 6th I figure that would have some impact on the numbers.

3) what is the explanation for a wheelie? is it extreme weight transfer, the back wheel accelerating faster than the front and "driving through" the front? Is a power wheelie one example but a clutch up something else?

OK .... I'll bite.

RAIN

If it's rains 1 inch ..... that's 1 inch deep..... doesn't matter if you measure
a 1 inch by 1 inch area or a 1 foot by 1 foot area..... although the bigger
the measurement area the more likely the result is accurate.

You can use a funnel but then your measurement area is the size of the TOP
of the funnel. Make sense ?

DYNO

Doesn't matter what gear the bike / car is in... measurement is relative.

Lower gears have more mechanical advantage but produce less work overall.

(Torque X RPM) / 5252 = Horsepower

Horsepower is a measure of torque x speed ( distance ) and while a lower
gear can twist harder ( more torque ) it cannot spin as fast ( MPH ) therefore
it all evens out.

Most shops use 2nd or 3rd gear on a bike.

WHEELIE

When your motorcycle accelerates, the rear wheel pushes forward on the tarmac.

Every action (force) has an equal and opposite reaction.

In this case, the opposite reaction is the entire motorcycle trying to rotate
in the opposite direction around the rear axle. The only thing stopping an
instant wheelie is the force of gravity applied to the the motorcycle...
the weight of the motorcycle / rider prevents the front wheel from lifting.
When the FORCE applied to accelerate exceeds the weight on the front of
the motorcycle it begins to lift.

As it lifts the weight gets closer to the pivot ( rear axle ) and makes it easier
and easier to lift.... this is why as you approach the BALANCE POINT it
becomes easier to apply too much force and over rotate the bike and flip it.

No difference between a "power" wheelie" and a "clutch-up" except the rate
at which you apply the force.... think of the clutch up like a "snatch" lift and
the power wheelie like a "dead" lift.

If it's rains 1 inch ..... that's 1 inch deep..... doesn't matter if you measure
a 1 inch by 1 inch area or a 1 foot by 1 foot area..... although the bigger
the measurement area the more likely the result is accurate.

You can use a funnel but then your measurement area is the size of the TOP
of the funnel. Make sense ?

DYNO

Doesn't matter what gear the bike / car is in... measurement is relative.

Lower gears have more mechanical advantage but produce less work overall.

(Torque X RPM) / 5252 = Horsepower

Horsepower is a measure of torque x speed ( distance ) and while a lower
gear can twist harder ( more torque ) it cannot spin as fast ( MPH ) therefore
it all evens out.

Most shops use 2nd or 3rd gear on a bike.

WHEELIE

When your motorcycle accelerates, the rear wheel pushes forward on the tarmac.

Every action (force) has an equal and opposite reaction.

In this case, the opposite reaction is the entire motorcycle trying to rotate
in the opposite direction around the rear axle. The only thing stopping an
instant wheelie is the force of gravity applied to the the motorcycle...
the weight of the motorcycle / rider prevents the front wheel from lifting.
When the FORCE applied to accelerate exceeds the weight on the front of
the motorcycle it begins to lift.

As it lifts the weight gets closer to the pivot ( rear axle ) and makes it easier
and easier to lift.... this is why as you approach the BALANCE POINT it
becomes easier to apply too much force and over rotate the bike and flip it.

No difference between a "power" wheelie" and a "clutch-up" except the rate
at which you apply the force.... think of the clutch up like a "snatch" lift and
the power wheelie like a "dead" lift.

Tom

BEST...POST...EVER in this thread at least

yeah, so I realized #1 doesn't matter, sometimes I get stuck on details and don't look at the big picture where as long as the top is the same size as the bottom it's all the same.

alright, I'm happy with these answers, you can have your supercharged Camry thread back now

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